Golf is a sport which challenges a player's skills in golf ball control with respect to its traveling directions and distances. Since an impacted golf ball demonstrates the characteristics of trajection movements, it is theoretically feasible to predict its movement based on the trajectory principles. It is therefore desirous to have a device capable of detecting and displaying data on a traveling golf ball based on these principles.
There have been some golf training devices that addressed this need. U.S. Pat. No. 4,146,230 provided a simple golf training device, i.e., a golf swing reforming device, for the detection of the movement of a club head. This device, however, did not generate data based on the actual movement of a golf ball.
While U.S. Pat. No. 4,542,906 disclosed a computer aided golf training device capable of detecting movement of a ball immediately after it was impacted by a club head, this device, however, has certain limitations as it may cause some inaccurate determinations for the trajectory movement of a golf ball. For instances, there is a detection-blind area between the light signal producing means holding part and the light signal detecting means holding part of that device in which the impacted ball will be traveling undetectedly due to the asymmetrical arrangements of the light emitting source and light signal detecting elements on said holding parts. In addition, detection errors may be occurred if the ball travels in a direction closer to the light emitting source so that a single crossing signal will simultaneously activate more than one light detecting elements due to the use of a divergent light source by this device. Furthermore, if the golf ball taking off at a very small vertical angle, calculations of this angle by this device is practically impossible or otherwise inaccurate because the spatial difference between the intercepting points of the ball with the first and the second light producing signals is insignificant to support such calculations.
The light emitting sources of an optical net may vary in types. For instance, the traditional infrared (IR) touch screen technology uses multiple IR emitting diodes (LED) to form a transmitting optical array. This technology would require a lots of LEDs if a relatively larger optical net is constructed to cover a large illumination area. Since the LED is not a coherent light source as the laser, the distance between the LED transmitters and detectors can not be too far because the optical signals between the adjacent transmitter-detector pairs may overlap to cause inaccurate detection. This limited factor may be correctable only if individual LED is independently focused to reduce signal overlapping or modulated so each LED light can be distinguished. These approaches lead to a much higher cost and more complicated design, and are not practical or too costly in constructing a golf training device whose optical net is intended to cover a large area, i.e., 4 to 8 feet or so.
It is therefore an object of the present invention to overcome the disadvantage of the above-mentioned device and to provide a golf training device capable of performing the calculation of a variety of relevant data by a simple and in a highly accurate manner.
It is a further object of the present invention to provide a golf training device capable of forming a laser-based, two-dimensional, single planar and highly symmetrical optical sensor net for detecting movement of a golf ball impacted to display data on the ball.